干旱是造成冬小麦减产的最主要的自然灾害之一，然而气候变化背景下干旱发生的机制及其时空格局仍不明确。本研究基于华北平原1958-2015年气象站点的长时间序列气象数据，采用敏感性分析，M-K检测以及斜率估计等方法，分析了不同气象因素对冬小麦干旱风险的影响机制。结果表明，近60年来冬小麦生育期内气象因子发生了显著的变化，导致冬小麦面临着严重的干旱风险（生长季内水分亏缺量达到350 mm），尤其在拔节-抽穗和抽穗-成熟期这两个产量形成的关键时期面临的干旱威胁更加严重。冬小麦生育阶段的干旱风险和气象因子呈现较大的时空分异特征。尽管降水对于干旱风险格局起主导作用，但是在冬小麦生长的关键阶段，气温升高和相对湿度降低等气象因素的变化都将加剧其干旱风险。过去几十年中近90%的气象站点温度都呈明显的上升趋势，如果未来气温持续升高，冬小麦的水分亏缺和干旱风险将会进一步加剧。研究结果可为作物生产有效适应未来气候变化和保障区域粮食安全提供基础支撑。

Salinity is one of the major abiotic factors affecting the growth and productivity of crops in Hetao Irrigation District, China. In this study, the salinity tolerances of three local crops, wheat (Triticum aestinum L.), maize (Zea mays L.) and sunflower (Helianthus annuus L.), growing in 76 farm fields are evaluated with modified discount function. Salinity ecological zones appropriate for these local crops are characterized and a case study is presented for crop salinity ecological zoning. The results show that the yield reductions of wheat, maize and sunflower when grown in saline soils are attributed primarily to a reduction in spikelet number, 1 000-grain weight and seed number per head, respectively. Sunflower is the most tolerant crop among the three which had a salinity tolerance index (ST-index) of 12.24, followed by spring maize and spring wheat with ST-Indices of 9.00 and 7.43, respectively. According to the crop salinity tolerance results, the arable land in the Heping Village of this district was subdivided into four salinity ecological zones: the most suitable, suitable, sub-suitable and unsuitable zones. The area proportion of the most suitable zone for wheat, maize and sunflower within the Heping Village was 27.5, 46.5 and 77.5%, respectively. Most of the most suitable zone occurred in the western part of the village. The results of this study provide the scientific basis for optimizing the local major crop distribution and improving cultural practices management in Hetao Irrigation District.

It had been demonstrated that the strong and highly significant quantitative trait locus (QTL) can affect protein percentage on Bos Taurus Autosome 3 (BTA3) at the position 52 cM, near the microsatellite DIK4353, with the 95% confidence interval spanning from 25 to 57 cM in Chinese Holstein population using QTL-express, MQREML, and GRIDQTL softwares. This study herein focused on such region of fine mapping QTLs for milk production and functional traits with 16 microsatellite markers with coverage of 33 cM between the markers BMS2904 and MB099 on BTA3 in a daughter-designed Chinese Holstein population. A total of 1 298 Holstein cows and 7 sires were genotyped for 16 microsatellites with ABI 3700 DNA sequencer. The variance components QTL linkage analysis (LA) and linkage-disequilibrium (LD) analysis (LA/LD) was performed to map QTLs for 7 traits, i.e., 305-d milk yield, fat yield, protein yield, fat percentage, protein percentage, somatic cell score and persistency of milk yield. Four strong and highly significant QTLs were detected for fat yield, fat percentage, protein percentage and somatic cell score at the position 40, 30, 27 and 26 cM, respectively. Two minor QTLs for milk yield and persistency of milk yield were identified at 42 and 46 cM, respectively. These findings provided a general idea for the fine mapping of the causal mutation for milk production and functional traits on BTA3 in the future.